Security is a staff of sometime-patrons who choose to work for the establishment in quelling in-bar conflicts.

"Ooh -" The girl flips back in her transcription. "And we go back to the time the door took us from, right? So basically they can put in work and go back home without having wasted any time?"

Under normal circumstances, yes. Your universe will not wait for you if you are not in fact ever going to return to it, or if you cannot do so until conditions requiring the passage of time in your universe are met.